CVE-2026-61704

Description

Link Preview JS extracts web links information. Prior to 4.0.4, the resolveDNSHost mitigation in index.ts validates one resolved IP address but fetches the original hostname, allowing an attacker-controlled DNS server to return a public address during validation and a loopback or internal address during the final connection. This DNS rebinding condition bypasses the SSRF protection and can cause the server-side preview fetch to reach internal HTTP resources. Redirect handling is affected by the same validation-to-fetch mismatch. This issue is fixed in version 4.0.4.

References

• https://github.com/OP-Engineering/link-preview-js/commit/6ee25043dd60b097eb70b4ce049aac94b28239e3
• https://github.com/OP-Engineering/link-preview-js/commit/f3a3dd84adbb9d32d06a933f44ff3eaa837f9a12
• https://github.com/OP-Engineering/link-preview-js/pull/181
• https://github.com/OP-Engineering/link-preview-js/releases/tag/4.0.4
• https://github.com/OP-Engineering/link-preview-js/security/advisories/GHSA-cpjf-6666-r8fx